Various forms of network storage systems are known today. These forms include network attached storage (NAS), storage area networks (SANs), and others. Network storage systems are commonly used for a variety of purposes, such as providing multiple users with access to shared data, backing up critical data (e.g., by data minoring), etc.
A network storage system can include at least one storage system, which is a processing system configured to store and retrieve data on behalf of one or more storage client processing systems (“clients”). In the context of NAS, a storage system may be a file server, which is sometimes called a “filer”. A filer operates on behalf of one or more clients to store and manage shared files in a set of mass storage devices, such as magnetic or optical disks or tapes. The mass storage devices may be organized into one or more volumes of a Redundant Array of Inexpensive Disks (RAID). In a SAN context, the storage server provides clients with block-level access to stored data, rather than file-level access. Some storage servers are capable of providing clients with both file-level access and block-level access.
As storage technology evolves, the storage capacity of mass storage devices continues to increase. For example, 2 terabyte (TB) disk drives are currently available and 4 TB and 8 TB drives will be available in the near future. As the storage capacity of the mass storage devices increases, the storage capacity of a typical aggregate (i.e., a number of RAID groups forming a storage container for file systems and/or LUNs) will grow. Additionally, the number of mass storage devices making up an aggregate will tend to decrease. With fewer mass storage devices making up an aggregate, the input/output (I/O) operations will be spread across fewer devices, negatively impacting I/O performance. Furthermore, larger mass storage devices will result in longer RAID reconstruct times.